Modern mobile communication devices need to be small and lightweight but have to support multiple frequency bands or multiple communication standards, such as GSM (Global System for Mobile Communications), (W)CDMA ((Wideband) Code Division Multiple Access), or LTE (Long-Term Evolution). LTE, a communication standard of the fourth generation, 4G, enables operating two antennas simultaneously. Multi-antenna transmission modes in LTE systems can improve the service capabilities of a communication device. Therefore, a mobile communication device can comprise a main antenna and a diversity antenna.
From U.S. Pat. No. 7,505,006 B2, an antenna arrangement comprising a coupling antenna element and an extension element is known. An antenna element has a first resonant frequency and a first bandwidth and the extended conductive element has a second resonant frequency and a second bandwidth. Thus, an antenna arrangement is provided that can cover a broad range of frequencies.
From U.S. Patent Publication No. 2010/0081407 A1 filter stages for high data rates are known. In one embodiment of a “diversity receiver” a switch has a switching state in which an antenna is electrically connected to an impedance which is chosen so that a phase angle caused by the reflection allows for optimizing mutual coupling between the antenna and a further antenna.
However, current demands towards smaller communication devices inhibit designers of modern communication devices to include additional antenna components within modern communication devices although communication devices with improved antenna performance are needed. An improved antenna performance e.g., helps saving energy.